In the transfer of electrical power from one group of conductors to another group, such as by switches, permanent electrical connectors and the like, it has been the practice to utilize connector plates or bus bars of low impedance and relatively large surface area to provide the desired electrical contact between conductors. This generally requires that the conductors and the connector plates have opposed surfaces which are substantially flat throughout their entire area to assure positive electrical contact over at least part of these areas to minimize electrical losses. Since the surfaces are never completely flat, The surfaces present a relatively small number of randomly located point contacts and, as a result, the quality of the electrical connection is not as high as it should be to minimize the losses mentioned above. Moreover, the face-to-face contact between heavy-duty electrical conductors and bridging parts requires considerable pressure to keep the contact surfaces in proper engagement with each other, and it is not possible to maintain these pressures over time. These pressures, especially if there is to be relative movement periodically between the elements forming a connection, such as in a switch or in plug-in devices, are the cause of considerable design and maintenance problems.
Due to the size of the conductors, it is usually necessary to provide an expansion joint capability because of temperature cycling. In conventional joints, these are made from braid or thin sheet assemblies. Thus, any improvements in electrical connectors for conductors of this type requires that this capability be taken into consideration.
A need has, therefore, arisen for improvements in releasable electrical connectors of the type having a number of heavy-duty conductors to be interconnected so as to transfer electrical power from one group of conductors to another group. The need is based upon a high quality connection having low energy losses and a requirement that this connection be easily assembled and disassembled, that the pressure required for assembly will not place high stresses on the fastener means, and that the connection maintain its electrical quality over long time periods, thereby reducing maintenance cost and cost of production.